Synthesis of nitrogen-functionalized cyclohexanes using chemoselective conjugate addition of phenyllithium to linear omega-Nitro-alpha,beta,psi,omega-unsaturated ester and subsequent stereoselective intramolecular nitro-Michael cyclization.

摘要

Nitrogen-functionalized cyclohexane derivatives with three contiguous chiral centers were synthesized by nitroalkene-selective conjugate addition of phenyllithium to a omega-nitro-alpha,beta,psi,omega-unsaturated ester and subsequent stereocontrolled intramolecular nitro-Michael cyclization with cesium fluoride and a quaternary ammonium bromide. The cyclohexanes were applicable to the total synthesis of alpha-, beta- and gamma-lycoranes.